PTGER4 and infectious otitis media: The ratio of p-β-catenin Ser552 to β-catenin was quantified at day 64 following administration of AOM in Hpb-infected mice given a vehicle control (Veh) to Hpb-infected mice administered prostaglandin E2 receptor 2 (EP2) and EP4 antagonists (PF-04418948, ONO-AE3-208; 10 mg/kg) i.p. during Hpb infection (Fig. 6A).